i'm blocked by two issues and feeling about 2" tall. i removed the lower intake manifold to replace the gaskets, marking the rotor relative to the distributor housing. The manifold is back on. The distributor will not seat completely when i install it aligned as marked. But it will seat properly if I install it mis-aligned.

The botton end of the distributor shaft looks like it has an alignment bar, making it installable either correctly, or rotated by 180 degrees. Apart from this i'm clueless about what is going on. any ideas?

 

the "alignment bar" is what drives the oil pump....you cannot align with the mark you made because the cam gear and distributor gear do not have straight teeth they are slanted so you must "align" 1 to 2 teeth off of your mark and when the distributor fully seats it should be in line with your mark....watch the rotor when you reinstall the distributor and you should "pick up" on how to set it pretty quick....REMEMBER small adjustments on either side of the mark you made will "drop it right in to place it just takes a little patience and a "BEER or two"

 

thanks ... when i anticipated the 1 or 2 teeth off, i could get the dist to end up in the aligned position correctly, but it did not fully seat, remaining high by 1/8 or so. maybe the oil pump or the engine rotated, but i can't imagine this happening ... the truck has been in gear with the emergency brake set since the beginning ... and the serpentine belt was one of the first to be removed. If either the pump or engine has in fact rotated inadvertently, how to figure out which? It would much simpler to rotate the oil pump with the a screw driver ... but maybe nothing has rotated and there is some other explanation ... i found this:

http://www.netquickposse.org/keeper/distrib.pdf

it is Document ID # 358641

but it pertains to S10s

is there a way to get the corresponding document for my engine?

 

here is what I would do since Im not there to help or "put my hands" on the problem I would drop the oil pan and oil pump.......install the distributor then reinstall the oil pump................on a side note did you wiggle the rotor back and forth when you got to the 1/8th inch off? some times it will drop in if you do that but it sounds like you just didnt hit the right tooth yet

 

thanks again ... i'm going to have another go at this afternoon ... assuming that i have found the right tooth, the big issue seems to be to decide if it is the oil pump or the engine that has rotated ... i'll assume it is the oil pump that has inadvertantly rotated, but i will first double check check your lead about wiggling the rotor ...

 

yaaaaaaa ! news at 11

it runs ! thanks for helping me out ! ended up rotating the oil pump drive shaft to get it to seat properly ... gratefully the rotor ended up in perfect alignment with the housing, making me confident that the it was the rotor and not the engine which had turned inadvertently ... still not sure how the oil pump turned so much. it was 18 degrees F out, not including windchill factor. and by the time i got to the battery cables i could barely use my fingers. hopefully the RTV has cured okay, applied it yesterday in about 40deg weather. got the engine warmed up a bit this evening, registering 160 deg or so ... so maybe this will help the curing process. took about 14 hours over three days, but could probably finish in half that next time. the garage had originally told me 3-400 then they upped it to 5-600 when i made an appointment and asked for a quote. they had my trust, then lost it ... and i am poorer for it.

 

distributor housing and rotor are in correct alignment in this photo. the OE dist housing has the number 6 marked at "B", the magic marker line at "A" was placed prior to disassembly. On initial reassembly, the dist would fully seat only when the dot at "C" was at "B". I used a protractor to measure the angle. 61 degrees. There are 13 splines on the distributor shaft, making the off-by-a-tooth result in a 28 degree misalignment ... so the oil pump had somehow rotated about 2 teeth's worth.

 

so you might be able to adjust out the diffrence...if not try to get a LONG standard screw driver and reset the oil pump...or like I said before pull the oil pan and pump install the distributor then reinstall the oil pump and pan.......its kind of a PITA but it may be the only way to go.......did you try and adjust out the diffrence in rotor position to get it back in time?

 

hi chris, thanks! ... sorry, i'm not sure what you mean by "adjust out" ..... but i did end up using a screwdriver, an overview is in this thread about three posts earlier. rotating the oil pump shaft was all that was necessary.
the image of the rotor was just a follow up.

i've now put about 20 miles in five trips on the truck. SES has not lit. runs ok. but there is almost no heat in cab.

here is another image ... the red line points to a tooth ... lines A and B mark the tooth's edge at the top left and bottom left. the amount of twist in the tooth is "x", which i calculate in minute ....

line C marks the top left edge of another tooth, two teeth away.

using a ruler on the image, the distance "x" is 3/4ths of the distance between lines C and A .... in other words, the amount of twist, "x", is 1.5 teeth ...

there are 13 teeth, so the teeth are spaced about 28 degrees ... so the amount of twist is about 42 degrees ...

the moral of it is that to reinstall the distributor, begin by turning the rotor counter clockwise by about 45 degrees from where it is supposed to end up ...

i suppose my calculations could be wrong, let me know ... but 45 degrees is about what it took if i remember correctly. to me 45 degrees is counter intuitive given how close the teeth look on the actual shaft. these calculations are after the fact. maybe they will be helpful to someone else doing this for the first time (like me).

 

no problem Im glad you got it running.....what I ment by "adjusting it out" is an old school term for setting the timing by loosining the distributor and rotating it back to your mark thus putting the engine "back in time".........as far as your calculations.....they are WAY beyond me (math makes my head hurt!)